Packaging bag

ABSTRACT

The present invention provides a packaging bag that is free from leakage of atmosphere conditioner from its supply section, manufacturable at reduced cost and by simplified manufacturing processes, and useable under high temperature conditions. The packaging bag has an upper end portion serving as a supply section from which the atmosphere conditioner is supplied. The upper end portion is formed such that a position of an end portion of a front side of a packaging material and a position of an end portion of a back side of the packaging material are shifted from each other, and a relatively protruding end portion is folded and welded onto an outer surface of the other end portion.

TECHNICAL FIELD

The present application is based on JP Appl. No. 2015-201495 filed on Oct. 9, 2015, the content of which is incorporated herein.

The present invention relates to a packaging bag containing an atmosphere conditioner, such as an oxygen absorbing agent and a desiccant.

BACKGROUND ART

An atmosphere conditioner, such as an oxygen absorbing agent and a desiccant, is normally stored in a rectangular packaging bag and used. This packaging bag is typically manufactured using a rotary, three-way seal bag manufacturing and filling apparatus. In this apparatus, a packaging material constituting a packaging bag is formed into a bag shape, a nozzle is inserted from the remaining opening side (supply side) of the bag, an atmosphere conditioner is supplied from the nozzle into the packaging bag, and the supply side is then welded to hermetically close the supply side to form the packaging bag.

However, according to the above-mentioned method, the powdery atmosphere conditioner supplied from the supply side of the packaging bag may adhere to a sealing part of the supply side which is to be welded in the subsequent step. In such case, when the supply side is sealed, the atmosphere conditioner enters the sealing part between the packaging materials at the supply side. Such phenomenon is undesirable in terms of the appearance of the packaging bag, as well as in terms of potential outside leakage of the atmosphere conditioner which has entered the sealing part.

Under such circumstances, a technique has been proposed which covers the supply side of the packaging bag with an adhesive tape (see Patent Document 1).

CITATION LIST Patent Document

Patent Document 1: JP2013-107682 A

SUMMARY Technical Problem

However, this method requires the steps of preparing an adhesive tape which is a separate member from the packaging material and attaching the adhesive tape onto the supply side of the packaging bag, which requires extra cost and complicates the manufacturing processes. In addition, in a situation in which the packaging bag needs to be subjected to heat treatment at a high temperature for sterilization purposes, etc., a solvent may dissolve out from the adhesive tape, depending on the temperature, and such packaging bag can be used only at limited temperatures.

The present invention has been made in view of the above circumstances, and it is possible to provide a packaging bag that is free from leakage of atmosphere conditioner, such as an oxygen absorbing agent and a desiccant, from its supply section, manufacturable at reduced cost and by simplified manufacturing processes, and useable under high temperature conditions.

Solution to Problem

The inventors of the present invention have found that the above object can be achieved by, in a supply side of a packaging bag, shifting the positions of respective end portions of a front side and a back side of the packaging material and folding and welding a protruding end portion onto an outer surface of the other end portion, and completed the invention.

Specifically, the present invention includes the following aspects:

(1) A packaging bag containing an atmosphere conditioner, comprising: a supply section from which the atmosphere conditioner is supplied, wherein the supply section is formed such that a position of an end portion of a front side of a packaging material and a position of an end portion of a back side of the packaging material are shifted from each other and a relatively protruding end portion is folded and welded onto an outer surface of the other end portion.

(2) The packaging bag according to (1), wherein an opposing part that opposes the supply section is formed by folding the packaging material.

(3) The packaging bag according to (1) or (2), wherein the end portions of the front and back sides of the packaging material, whose positions are shifted from each other at the supply section, are each constituted by a plurality of layers made of different materials, and an inner layer of the protruding end portion and an outer layer of the other end portion, which are made of different materials, are welded together.

Advantageous Effects of Invention

According to the present invention, it is possible to provide a packaging bag for an atmosphere conditioner, such as an oxygen absorbing agent and a desiccant, which can be manufactured at low cost and by a simplified manufacturing process without leakage of the atmosphere conditioner from a supply section of a packaging bag and which can be used under high temperature conditions. By using this package for atmosphere conditioner according to the present invention, it is possible to retain the freshness and quality of articles, such as foods and pharmaceutical products, without causing the articles to be contaminated.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1(a) is a front view of a packaging bag and FIG. 1(b) is a side view of the packaging bag.

FIG. 2 is a cross-sectional view of the packaging bag, showing how one end portion in a supply section is folded.

FIG. 3 is a cross-sectional diagram showing a packaging bag according to another aspect.

FIG. 4 is an illustration explaining a step of forming a lower end by folding a packaging material.

FIG. 5 is an illustration explaining a step of welding right arid left ends of the packaging material.

FIG. 6 is an illustration explaining a step of introducing an atmosphere conditioner by inserting a nozzle into the packaging material with the three ends thereof being closed.

FIG. 7 is an illustration explaining a step of folding an end portion at the supply section.

FIG. 8 is an illustration showing a packaging bag with an indicator attached thereto.

DESCRIPTION OF EMBODIMENTS

Preferred embodiments of the present invention will now be described with reference to the attached drawings. In the following description, the same elements will be denoted by the same reference symbols, and redundant explanations thereof will be omitted. In addition, positional relationships such as the upper, lower, right and left are based on the positional relationships shown in the drawings, unless otherwise indicated. Further, the dimensional ratios in the drawings are not limited to those illustrated in the drawings. It should be noted that the following embodiments are merely examples for explaining the present invention and the present invention is not limited to such embodiments.

FIG. 1(a) is a front view showing the outline of a configuration of a packaging bag 1 according to the present embodiment and FIG. 1(b) is a side view showing the packaging bag 1. It should be noted that, in the specification of the present application, a side of the packaging bag 1 from which an atmosphere conditioner is supplied (the upper side in FIGS. 1 and 2) is defined as an upper side. The “atmosphere conditioner” as referred to herein is something that adjusts the ambient atmosphere, such as an oxygen absorbing agent and a desiccant. “AGELESS” (registered trademark; manufactured by MITSUBISHI GAS CHEMICAL COMPANY, INC.) is known as a representative product of oxygen absorbing agents.

As shown in FIGS. 1(a) and 1(b), the packaging bag 1 is formed in, for example, a rectangular bag-like shape with an atmosphere conditioner A contained therein.

A lower end portion 20 of the packaging bag 1 is formed by folding a packaging material 30. In other words, the lower end portion 20 is formed continuously and a lower edge thereof is curved so as to be arcuate.

A left end portion 21 and a right end portion 22 of the packaging bag 1 are formed by welding a front side 31 and a back side 32 of the packaging material 30 together.

An upper end portion 23, serving as a supply section from which the atmosphere conditioner A is supplied, is formed as follows. The positions of respective end portions 31 a, 32 a of the front side 31 and the back side 32 of the packaging material 30 are shifted vertically as shown in FIG. 2, and the relatively protruding end portion 32 a of the back side is folded and welded onto the outer surface of the end portion 31 a of the front side.

As the packaging material 30, a single film may be employed or two or more films may be employed in an overlapping manner (with only a seal part thereof being welded). The film(s) may employ a single-layer film or a multilayered film including two or more layers made of different materials. FIG. 2 shows a configuration in which two two-layer films 33 and 34 are used in an overlapping manner for each of the front side 31 and the back side 32 of the packaging material 30. The outer film 33 has a two-layer structure including an inner layer 40 made of, for example, polyethylene (a first material) and an outer layer 41 made of a material having a higher melting point than that of the first material, such as polyethylene terephthalate or nylon (a second material). The inner layer 40 made of the first material may employ a heat-sealable material. Examples of the heat-sealable material may include one or more types of films, sheets or coating films made of resins such as low density polyethylene, middle density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-α-olefin copolymer polymerized using a metallocene catalyst, polypropylene, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, acid-modified polyolefin resins obtained by modifying polyolefin resin such as polyethylene or polypropylene with unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid and itaconic acid, polyvinyl acetate resins, poly(meth)acrylic resins, polyvinyl chloride resins.

The inner film 34 has a layer 42 made of, for example, paper or nonwoven fabric (third material) and a layer 43 made of a heat-sealable material similarly to the first material. In the present embodiment, the outer film 33 is longer than the inner film 34 and an end portion 32 a of the back side 32 of the packaging material 30 is formed only of the outer film 33. The end portion 32 a of the back side 32 of the packaging material 30 is folded toward an end portion 31 a of the front side 31 and an inner surface of the inner layer 40 of the end portion 32 a and an outer surface of the outer layer 41 of the end portion 31 a are welded together, wherein the inner layer 40 and the outer layer 41 are made of different materials.

Although the end portion 32 a is constituted only by the outer film 33 in FIG. 2, the end portion 32 a may be a single multilayer film containing both the outer film 33 and the inner film 34. In other words, the end portion 32 a may be constituted by a single four-layer film, instead of two two-layer films of the outer film 33 and the inner film 34. FIG. 3 shows a configuration in which the end portion 32 a is constituted by a single four-layer film. In this configuration, the inner surface of the layer 43 of the end portion 32 a and an outer surface of the layer 41 of the end portion 31 a are welded together.

An example manufacturing method of the packaging bag 1 will now be described below. First, as shown in FIG. 4, the rectangular packaging material 30 is folded. In this process, the packaging material 30 is not folded at the center thereof but is instead folded such that a portion serving as the end portion 32 a of the back side 32 remains at the top of the bag. Specifically, the front side 31 is folded onto the back side 32 with a folding line shifted from the center line of the packaging material 30 toward the front side 31 (the lower side in FIG. 4) so that the end portion 32 a is exposed at the top of the back side 32. As a result, the lower end portion 20 is formed at the lower edge. During this process, the inner layer film 34 is arranged in advance on the inner side of the packaging material 30. Next, as shown in FIG. 5, the left and right end portions are welded so as to form the left end portion 21 and the right end portion 22. As a result, a bag is formed with the upper end portion 23 being opened and the other three ends (the lower end portion 20, the left end portion 21 and the right end portion 22) being sealed. Next, as shown in FIG. 6, for example, a nozzle B is inserted from the opening at the upper end portion 23 to inject the atmosphere conditioner A into the bag so as to fill the bag. As shown in FIG. 7, the end portion 32 a of the back side 32 at the upper end portion 23 is then folded onto the outer surface of the end portion 31 a of the front side 31 and the end portion 32 a and the end portion 31 a are welded together. As a result, the packaging bag is completed with the four ends thereof being sealed and with the atmosphere conditioner A contained inside, as shown in FIGS. 1 and 2.

According to the present embodiment, the upper end portion 23 serving as a supply section for supplying the atmosphere conditioner A is formed by shifting the positions of the respective end portions 31 a and 32 a of the front side 31 and the back side 32 of the packaging material 30, folding the relatively protruding end portion 32 a onto the outer surface of the other end portion 31 a and welding the end portions 31 a, 32 a together. Therefore, the atmosphere conditioner A inside the bag will not leak from the upper end portion 23. Since the end portion 32 a is folded and welded onto the other end portion 31 a and such process does not require an additional member, such as an adhesive tape, it is possible to eliminate extra cost and simplify the manufacturing processes. In addition, the bag does not include an adhesive tape and such bag can be used under high temperature conditions.

Furthermore, since the end portion 32 a of the back side 32 of the packaging material 30 is folded onto the outer surface of the end portion 31 a of the front side 31, the upper end portion 23 is constituted by three layers including, from the front surface side thereof, the end portion 32 a of the back side 32, the end portion 31 a of the front side 31 and the end portion 32 a of the back side 32, and the strength of the upper end portion 23 is therefore enhanced. As a result, it is possible to suppress breakage or deformation at the supply section for supplying the atmosphere conditioner in the bag 1, and it is therefore possible to prevent leakage of the internal atmosphere conditioner A. Since such packaging bag 1 is difficult to unseal, it is possible to prevent the packaging bag 1 from being accidentally unsealed and the internal atmosphere conditioner A from being swallowed by mistake,

Since the end portion 32 a of the back side 32 of the packaging bag 30 is folded onto the end portion 31 a of the front side 31, another member can be attached to the packaging bag 1 by sandwiching such member between the end portions during this process. For example, as shown in FIG. 8, an indicator 50, such as an oxygen indicator and a humidity indicator, which will be used together with the packaging bag 1 can be sandwiched between the end portion 32 a and the end portion 31 a so as to be attached to the packaging bag 1.

According to the present embodiment, the lower end portion 20, being an opposing part which opposes the upper end portion 23 serving as the supply section of the packaging bag 1, is formed by folding the packaging material 30. With such configuration, edges of both the opposing upper end portion 23 and lower end portion 22 are continuously curved in an arcuate manner. Therefore, in a situation in which the packaging bag 1 is passed through a narrow space, such as when the packaging bag 1 is inserted into another bag from its opening, the packaging bag 1 can be smoothly passed without being caught by anything, and such packaging bag 1 has excellent handleability.

Although preferred embodiments of the present invention have been described with reference to the attached drawings, the present invention is not limited to such example. A person skilled in the art would obviously conceive of a variety of modifications and improvements within the scope of ideas to be presented in the scope of the claims. It should be understood that such modifications and improvements also belong to the technical scope of the present invention, as a matter of course.

Although the packaging bag 1 has a square shape in the embodiment above, it may have other shapes, such as a triangular shape. The number of supply sections of the packaging bag 1 is not limited to one, and may be two or more. The layer structure of the packaging bag 1 is not limited to those described in the embodiment above and any other known layer structures may be applied to the present invention. The above-mentioned manufacturing method of the packaging bag 1 is merely an example and other manufacturing methods may be used. For example, the present invention is applicable not only to a manufacturing method which produces the packaging bag 1 in a one-by-one basis but to a manufacturing method which produces a plurality of packaging bags 1 together at the same time.

INDUSTRIAL APPLICABILITY

The present invention is useful in providing a packaging bag that is free from leakage of atmosphere conditioner from its supply section, manufacturable at reduced cost and by simplified manufacturing processes, and useable under high temperature conditions.

REFERENCE SIGNS LIST

1: packaging bag

20: lower end portion

21: left end portion

22: right end portion

23: upper end portion

30: packaging material

31: front side

31 a: end portion

32: back side

32 a: end portion

A: atmosphere conditioner 

1. A packaging bag containing an atmosphere conditioner, comprising: a supply section from which the atmosphere conditioner is supplied, wherein the supply section is formed such that a position of an end portion of a front side of a packaging material and a position of an end portion of a back side of the packaging material are shifted from each other and a relatively protruding end portion is folded and welded onto an outer surface of the other end portion.
 2. The packaging bag according to claim 1, wherein an opposing part that opposes the supply section is formed by folding the packaging material.
 3. The packaging bag according to claim 1, wherein the end portions of the front and back sides of the packaging material, whose positions are shifted from each other at the supply section, are each constituted by a plurality of layers made of different materials, and an inner layer of the protruding end portion and an outer layer of the other end portion, which are made of different materials, are welded together.
 4. The packaging bag according to claim 2, wherein the end portions of the front and back sides of the packaging material, whose positions are shifted from each other at the supply section, are each constituted by a plurality of layers made of different materials, and an inner layer of the protruding end portion and an outer layer of the other end portion, which are made of different materials, are welded together. 